Construction of surfacings for roadways, sidewalks, and the like



' Patented May 22,1928.

UNITED STATES AUGUST E. SCHUTTE. OF NORTHIBORO, MASSACHUSETTS.

CONSTRUCTION OF SURFACINGS FOR ROA DWAYS, SIDEWALKS, AND THE LIKE.

No Drawing.

My invention relates to the upper course or wearing surface ofpavements, sidewalks, floors and the like and particularly to that typewhich is composed of bitumen cementing mineral aggregate and having itscementing value augmented with reinforcing fibre. I have been granted aU. S. Patent N 0. 1,265,259 dated May 7, 1918 for the use of asbestosfibre for this purpose, but I have found that the asbestos supply islocated principally in Canada, practically restricting the use of ittoareas close to the source of supply on account of the great weight andtherefore costly freight on the material. I have now found thatvegetable fibres such as jute, cotton, etc., if specially prepared,treated and handled according to my method can be used as an admixtureto bitumen without destroying the usefulness of the fibre through heat.

Numerous attempts have been made to use vegetable fibre as an ingredientin bitumi' nouspavements, but usually such fibre was destroyed throughheat or made brittle and useless during the process of the manufa'ctureof the wearing surface. Furthermore, it was found that the comminutionand separation of such fibre was a difiicult matter, requiring costlymachinery and producing a material which will, instead ofmixing throughthe whole mass, become balled and bunched, making it impossible toproduce a homogeneous mixture with the bituminous cement. r

I have discovered that woven fibre such as burlap bags, cotton rags,etc., if they are first saturated and impregnated with a bituminouscompound, can without balling or bunching easily be separated and cut upand mixed with the hot bituminous cement which forms aeementing mediumfor the aggregate.

In describing my invention I 'will speak of its use for constructionofroadways'and will confine myself to the use of old burlap bags althoughit is applicable to other fibrous materials for it is obvious that otherfibrous materials from other sources can be used in exactly the samemanner.

It is a wellknown fact that burlap bags or other rags are an article ofcommerce procurable any where thus the high freight problem is entirelyeliminated. Vegetable fibre, having less than half the specific gravityof asbestos, can be used in great deal smaller quantities and produceprac- Application filed December 16, 1925. Serial No. 75,868.

tically the same result. To practice my invention, l procure burlapwaste for example such as bags, put them through a vat or tankcontaining asphalt of the proper penetration, eliminate the excess ofasphalt by putting the material through a set. of rolls or othersqueezing device and then allow the thus saturated material to enter acutting machine which is heated-and which has, as its principal element,a series of rotating knives which will cut the material into fibresabout A" in length or even longer if it is desired. This cut fibre isthen allowed to enter the asphalt in the mixing plant and is then, withthe asphalt, put into an appropriate mixer and there mixed-with asuitable mineral aggregate. It can then be handled in the usual manner,raked and rolled upon the foundation, which is to receive and retain it.

The fibre being saturated "with the bituminous cement cuts with asurprising ease, obviating all matting and tan lin and gives a mostexcellent material i or 51c reinforcement of the bituminous cement. Itdoes not shorten or change either ductility, adhesiveness orcohesiveness of the cement, but augments ever one of these qualities. Itchan es some 0 the cohesive properties into-ad esiveness b'y saturatingthe individual fibre, the frayed ends of which have a larger contactingarea with the mineral aggregate than if the fibre was not present. Thefibre being first saturated seems to withstand all the temperaturesconsistent with laying'the surface.

In describing the use of my compound I have not described theproportions of the various materials, as in general these are well knownto those skilled in the art. It is well known that in making a pavementcom- 7 fora given piece of pavement and the amount of fibrous materialused may depend on the wear to which the pavement may be put and toother conditions which those skilled in the art will understand. What Iclaim as my invention is 1. A method of producinga paving material whichcomprises first saturating vegetable fibre with a bituminous cement,then cutting the fibre into small particles and cool, comminuting themass, mixing mineral mixing it with bituminous and mineral maaggregatetherewith and then mixing the 10 terial. Whole with a. bituminouscement.

2. A method of making a bituminous 3. A pavement comprising a mineralag- 5 pavement composition which comprises addgregate cemented withevenly distributed ing to a vegetable fibre a bituminous comcomminutedvegetable fibre impregnated pound whereby the fibre will absorb the Withbitumen. compound, then allowing the product to AUGUST E. SCHUTTE.

